IMMUNOHISTOCHEMICALLY DEMONSTRATED EXPRESSION OF HLA-DR ANTIGEN IN COLORECTAL ADENOCARCINOMAS AND ITS RELATION AO CLINICOPATHOLOGICAL FEATURES

We studied 148 colorectal adenocarcinomas to clarify any correlation b etween HLA-DR antigen expression on tumor cells and histopathological features. Paraffin sections of formalin-fixed tissues were stained wit h HLA-DR antigen using the indirect immunoperoxidase technique. All th e tumor tissues were divided into two groups, depending on the inciden ce of HLA-DR-positive cells (greater and lesser than 50%). Carcinoma t issues with a higher incidence showed less mural invasion, lymphoducta l invasion, venous invasion, lymphonodular metastasis, and peritoneal metastasis. Tissues with a high HLA-DR reactivity were more often obse rved for Dukes' A and B stages, whereas those with a low HLA-DR positi vity were frequently Dukes' C and D stages. As for the cumulative surv ival rate, the group with high HLA-DR expression demonstrated signific antly better survival. We speculate that HLA-DR expression by colorect al cancer cells exerts a favorable influence on clinical course. (C) 1 995 Wiley-Liss, Inc.